PROFFITT, T. and ZUPANCICH, A. - Macro and microscopic wear analysis of the non-worked lateral edge of a large biface

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CATEGORY

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LANGUAGE

English

ABSTRACT

The paper illustrates the results of an experimentation undertaken to test the hypothesis that characteristic wear is accrued on the non worked lateral edge of a stationary partially buried handaxe. The work involved the production of a large biface and its use as a stationary object resting on surface made up of sediment. At this point, the authors carried out a macro and microscopic wear analysis of the non-worked lateral edge.

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PRODUCTION OF THE BIFACE

A large biface was knapped from fine grained flint - coming from Suffolk (England, UK) - using hard hammer percussion only with a quartzite hammer-stone. In order to achieve the large dimensions needed for the experimental design it was decided that large nodular flint would be used as opposed to large flakes.

The core was simply reduced through the bifacial removal of large flakes, with a constant left to right rotation of the core. This produced a sharp cutting edge across the entire circumference of the biface.

The experiment lasted 20 minutes.

EXPERIMENTATION

Fig. 1 - Biface fixed in the ground.

the way in which the biface was used to saw wood

Fig. 2 - Chopping activity.

The experiment was conducted on moist fine grained sediment, with moderate flint and chalk inclusions. The ground was prepared through the removal of all organic debris, such as grass, wood, as well as any large flint fragments. The biface was placed on a clear surface with no attempt to burry the edge in the sediment. The biface was stabilized between the knees so as to hold it in place during use.

A total of ten hazel branches with an average circumference of 2.5cm were worked. Two different activities were undertaken on the working edge of the bifaces: chopping of and removing the bark from the hazel branches. In total the bifac was used continually for two hours. During this period no attempt was made to stop the biface from becoming buried in the ground due to use.

RESULTS

On the working edge, typical damage patterns associated to the working of medium hard materials, such as wood (Hayden 1982;Semenov 1978) can clearly be seen. The edge is characterised by the presence of small (< 2mm), close step scars. In several cases these are overlapping, while most of the times their disposition is regular and their orientation is perpendicular. In addition, an overall light rounding characterise the working edge of the object.

pre_use_edge

Fig. 3 - Pre-use edge 1/2.

pre_use_edge2

Fig. 4 - Pre-use edge 2/2.

On the other hand, however, the majority of the non-worked edge, in contact with the sediment shows a significant degree of snapping as visible on figure 6. This type of damage is represented along most of the edge and is frequently in accompanied by a medium degree of rounding.

This snapping of the thin edges can be defined as a first stage of modification, appearing early on in the use cycle, no more than 30 minutes of use. Subsequently, rounding of the snapped edge occurs which can be defined as a second stage of modification, possessing a slower degree of development (Figs. 5, 6, 7).

snap_and_rounding

Fig. 5 - After-use edge - Snap and rounding.

snap_and_slight_rouding

Fig. 6 - After-use edge - Snap and slight rounding.

snap_rounding

Fig. 7 - After-use edge - Snap and rounding.

DISCUSSION AND CONCLUSION

This study has confirmed that specific types of wear occur on the non-utilised edges of a biface when used as stationary objects. Furthermore, a high degree of efficiency has been noticed in the use of the object as a fixed element.

These results do not allow the identification variation in hominin tool use, nor does it offer a definitive classification of wear patterns associated with fixed biface use.

This study should be taken as a preliminary step towards understanding the different wear patterns associated with this behavior. A great deal of further experimentation is required, where a wider range of material is worked, on a wider range of sedimentary layers. Further to this, a greater number of bifaces of differing sizes must be tested, and finally, similar patterns of wear must be sought in the archaeological record.

REFERENCES

Clark, J.D. (1974) Kalambo Falls Prehistoric Site Vol. 2. The Later Prehistoric Cultures.0 Cambridge: Cambridge University Press.

Grosman, L., Sharon, G., Goldman-Neuman, T., Smikt, O. and Smilansky, U. (2010) Studying post depositional damage on Acheulian bifaces using 3-D scanning. Journal of Human Evolution 30, 1-9.

Howell, F.C. (1966) Isimilia: a Palaeolithic site in Africa. Scientific American, 205, 118-129.

Hayden, B. (1979) Lithic Use-Wear Analysis. New York: Academic Press.

Isaac, G.L. (1977) Olorgesailie: Archaeological Studies of a Middle Pleistocene Lake Basin in Kenya. Chicago: Chicago Universtiy Press.

Kleidienst, M. R. and Keller, C. M. (1976) Towards a Functional Analysis of Handaxes and Cleavers: The Evidence from Eastern Africa. Man, New Series, 11, 2, 176-187

Semenov, S.A. (1964) Prehistoric Technology: an experimental study of the oldest tools and artefacts from traces of manufacture and use. London: Cory, Adams & Mackay.

Sharon, G. (2009) Acheulian Giant-Core Technology a Worldwide Perspective. Current Anthropology 50, 3, 335-367.